Electric circuit means for textile strand ends down detecting apparatus

ABSTRACT

Improved electric circuitry for use in an apparatus which travels a detector along textile strand processing machines such as spinning frames for determining the absence of ends of yarn from locations therealong at which such ends normally are present and for thereby locating ends down on the textile strand processing machines. The electrical circuitry disclosed herein incorporates detectors generally pulse electrical signals, pulse shaping circuits receiving pulse signals from the detectors and shaping the characteristics thereof, and logic circuits receiving shaped pulse signals and generating an output pulse on a determination that an end is absent from a location at which the same normally is present.

United States Patent Saunders [4 1 May 2,1972

[541 ELECTRIC CIRCUIT MEANS FOR TEXTILE STRAND ENDS DOWN DETECTINGAPPARATUS [72] Inventor: David W. Saunders, Fitchburg, Mass. [73]Assignee: Rarks-Cramer Company, Charlotte, N.C. [22] Filed: Oct. 1, 1970[2]] Appl. No.: 77,101

Related US. Application Data [63] Continuation-impart of Ser. No.866,265, Oct. 14,

1969, abandoned.

[52] US. Cl. ..57/34 R, 57/56, 57/81 [51] Int. Cl. ..D0lh l3/26,D01h13/16,D0lh 13/32 [58] Field of Search ..57/34 R, 56, 52-54,

[56] References Cited UNITED STATES PATENTS 3,099,829 7/1963Namonyi-Katz ..57/81 X Primary Examiner-Donald E. WatkinsAttorney-Parrott, Bell, Seltzer, Park & Gibson 57] ABSTRACT lmprovedelectric circuitry for use in an apparatus which travels a detectoralong textile strand processing machines such as spinning frames fordetermining the absence of ends of yarn from locations therealong atwhich such ends normally are present and for thereby locating ends downon the textile strand processing machines. The electrical circuitrydisclosed herein incorporates detectors generally pulse electricalsignals, pulse shaping circuits receiving pulse signals from thedetectors and shaping the characteristics thereof, and logic circuitsreceiving shaped pulse signals and generating an output pulse on adetermination that an end is absent from a location at which the samenormally is present.

18 Claims, 9 Drawing figures 1 May 2, 1972 United States Patent SaundersSHEET 10F 5 PATENTEDMAY 2 I972 INVENTOR:

ATTORNEYS PATENTEDMAY 2 I972 SHEET 2 OF 5 INVENTOR. bAvlb \MSAUNBEIZSATTORNEY5 PATENTEDMAY 2 I972 SHEET u [If 5 1 QM W. m M

s hm w D Am M k b am 5g W41 PATENTEDMAY 2 I972 3, 659,409

sum 5 a; 5

DISTANCE: (louvre-217 (QZ INVENTOR: DAVlD SAuNDExas MMJL1%M{ A NEYSELECTRIC CIRCUIT MEANS FOR TEXTILE STRAND ENDS DOWN DETECTING APPARATUSThis application is a continuation-in-part of copending application Ser.No. 866,265 filed Oct. 14, 1969, and now abandoned and entitledidentically to this application.

It has heretofore been proposed that the efliciency of operation incertain textile strand producing operations be improved by providingapparatus for detecting and reporting the ends down condition of textileyarn or thread forming apparatus such as spinning and twisting machines.In accordance with such proposals, apparatus is provided within atextile mill room, such as a spinning room, for moving detector meansalong the textile apparatus in a predetermined manner and forregistering the response thereof.

It is an object of the present invention to facilitate improveddetermination of the absence of ends of yarn from locations at whichends of yarn normally are present along textile strand processingapparatus such as spinning frames.

It is another object of this invention to provide improved electricalcircuit means for ends down locating and reporting systems which is moreaccurate and provides greater flexibility and adaptability to variousconditions, resulting in more positive and reliable operation undervarying practical textile mill conditions.

It is another object of this invention to provide improved electricalcircuit means for an ends down detecting and reporting system which iscompatible with peripheral circuit equipment such as computers which maybe available to and used in conjunction with the detector means. Moreparticularly, the electrical circuit means of the present inventionfunctions by the generation and processing of pulse electrical signalsand includes logic circuit means for between the absence and presence ofends of yarn on the traversed textile machine.

A further object of the present invention is the improvement of anapparatus of the general type described above wherein the detector meansis combined with a pneumatic cleaner for travel on a track along aplurality of yarn forming locations, and wherein enhanced compatibilitywith the traveling pneumatic cleaner is achieved.

Some of the objects and advantages of the invention having been stated,others will appear as the description proceeds, when taken in connectionwith the accompanying drawings, in which FIG. 1 is an end elevationview, partially in section, of a traveling pneumatic cleaner andspinning frame incorporating ends down detecting apparatus in accordancewith the present invention;

FIG. 2 is a perspective view, from one side and above, of certainportions of the structure illustrated in FIG. 1, showing an applicationof a first embodiment of the electrical circuit means of the presentinvention;

FIG. 3 is a perspective view generally similar to FIG. 2 of certainportions of the structure illustrated in FIG. 1, showing an applicationof a second embodiment of the electrical circuit means of the presentinvention;

FIG. 4 is a block diagram of alternative embodiments for the electricalcircuit means of the present invention;

FIG. 5 is a schematic circuit diagram of the first embodiment ofelectrical circuit means for the apparatus illustrated in FIGS. 1 and 2;

FIG. 6 is a schematic circuit diagram of the second embodiment ofelectrical circuit means for the apparatus illustrated in FIG. 3;

FIG. 7 is a schematic circuit diagram of a third embodiment ofelectrical circuit means for use with apparatus such as is generallyillustrated in FIGS. 1 and 2;

FIG. 8 is a schematic circuit diagram of a fourth embodiment ofelectrical circuit means for use with apparatus such as is generallyillustrated in FIGS. 1 and 3; and

FIG. 9 is a schematic circuit diagram of a fifth embodiment ofelectrical circuit means for use with apparatus such as is generallyillustrated in FIGS. 1 and 2.

Referring now more particularly to the drawings, there is generallyillustrated apparatus which travels detector means along textile strandprocessing machines such as spinning frames for detecting and reportingthe ends down conditions. As will be noted from FIGS. 1 and 2, thepresent invention is particularly concerned with apparatus in which thetravel of detector means results from the combination of electricalcircuit means with a traveling pneumatic cleaner generally indicated at10 mounted on a track generally indicated at ll for movement above andalong a plurality of spindles on at least one textile strand processingmachine such as a spinning frame generally indicated at 12. For a moreextensive discussion of the advantages and benefits which flow from sucha combination, attention is directed to United States Pat. No. 3,523,413issued Aug. 1 1, 1970 entitled Apparatus and Method for Detecting andRepo'ning Ends Down on Textile Machines and owned in common with thisapplication. As the broad relationship of the traveling pneumaticcleaner in FIG. 1 to the textile strand processing machine may be fullyunderstood from the disclosure in the aforementioned patent andreference therein made toother and further pertinent patent disclosures,the present application shall not repeat at length such discussion anddisclosure, but is directed to the particular improved electricalcircuit means for such ends down locating and reporting apparatus.

A textile strand processing machine such as the spinning frame 12conventionally has locations spaced therealong at which ends of yarnnormally are present during operation of the machine. In the spinningframe 12, such locations are related to the locations of spindlm l4spaced along the length of the machine, in that each end of yarn passesfi'om front delivery rolls of drafting systems 15 through a stationaryguide such as a pigtail 16, then to a rotating guide such as a traveler18 moving about a spinning ring, and onto a package or bobbin beingfon'ned at each spindle location. Thus at each spindle location aportion of the path of movement followed by an end of yarn presents theyarn moving generally along a line (namely between the front deliveryrolls and the pigtail 16) while another portion presents the yarn movingin a rotating balloon (namely between the pigtail l6 and the traveler18). As will be pointed out hereinafter, advantage is taken of thesecharacteristics of yarn movement in order to insure proper response indetermining the absence of ends of yarn from locations between thedrafting rolls l5 and spindles 14 at which such ends normally arepresent.

In accordance with the present invention, a determination of the absenceof ends of yarn from a textile strand processing machine such as aspinning frame is accomplished by electrical circuit means generallycomprising detector means generating a pulse electrical signal inresponse to the presence of ends of yarn, signal conditioning meanscomprising pulse shaping circuit means electrically connected to thedetector means for receiving and shaping pulse signals therefrom, logiccircuit means receiving shaped pulse from the pulse shaping circuitmeans and responsive to normal traversal of a textile machine fordistinguishing between absence and presence of ends of yarn and forgenerating an output pulse signal upon an end of yarn being absent andan output electrical device responsive to an output pulse from the logiccircuit means for registering an ends down condition thus sensed anddetermined. As to each of these elements which are in the electricalcircuit means of the present invention, certain alternatives areavailable and will be described more fully hereinafter.

In accordance with the present invention, the detector means providedpreferably are photosensitive means which have a predetermined field ofview and which generate pulse electrical signals in response tovariations in illumination in that field of view such as are indicativeof the presence of an end of yarn. Such photosensitive means is mountedfor traversal of the field of view along a plurality of locations, suchas spindles, at which ends of yarn normally are present, and the fieldsof view indicated by phantom line cones generally indicated at 20 inFIGS. 1 3 represent such fields of view of photosensitive means. Whilethe photosensitive means is enclosed, for protection and convenience inhandling, within an appropriate protective housing 21 (FIG. 1), neitherthe protective housing 21 nor a detailed representation of thephotoelectric means has been included in FIGS. 2 and 3, in order thatthe relative positioning of the field of view to elements of thespinning frame 12 may be more clearly seen. The photosensitive means ismounted for travel with the traveling pneumatic cleaner 10, generally asdescribed more fully in the aforementioned U.S. Pat. No. 3,523,413.

In FIGS. 1 2 phantom line cones 20 representing the field of view ofphotosensitive means are shown to be directed toward those portions ofthe textile strand processing machine at which ends of yarn normally aremoving in lines between the delivery rolls l5 and the pigtail 16. FIG. 3illustrates the direction of such phantom line cones 20 directed towarda portion of the textile machine at which ends of yarn are normallyballooned between the pigtails l6 and travelers on the rings 18. it iscontemplated by the present invention that the electrical circuit meansherein disclosed for detennining the absence of ends of yarn fromlocationsalong a spinning frame or the like may function in detectingends of yarn at least in either of these general areas at which ends ofyarns normally are present. in both instances, it is to be noted thattravel of the phantom line cones illustrated in FIGS. 1 3 longitudinallyof traversed textile apparatus will result in scanning of all locationstherealong at which ends of yarn are normally present.

In accordance with circuitry preferred for certain applications of thepresent invention, the photosensitive means incorporated in theelectrical circuit means is a photomultiplier device. As is generallywell known, a photomultiplier device is a vacuum tube structure in whichsecondary emission of electrons is used to amplify the effect of lighton an emissive surface in the device. When a photomultiplier device isarranged as photosensitive means having the field of view 20in FIGS. 13, electron flow through the device is determined essentially by therelative brightness of objects in the field of view 20 or across whichthe field of view moves. Thus, ends of yarn present in the field of view20 give rise to variations in electron flow in the photomultiplierdevice by virtue of the relative brightness of such ends of yarn againstthe background of the textile strand processing machine elements. Thisis true both in that portion of the machine at which ends of yarn movealong generally fixed lines from the delivery rolls to the pigtall 16 aswell as in that portion where the ends of yarn follow ballooned pathsbetween the pigtail l6 and a traveler, although the response of thephotomultiplier is in the latter instance subject to shifts in level asdisclosed more fully hereinafter.

The response obtained from a photomultiplier device or otherphotosensitive means may be enhanced by insuring that a significantdistinction in brightness exists. As discussed more fully in theaforementioned copending application, this is preferably accomplished bythe addition of a light source which illuminates the field of view ofthe photosensitive means and which moves therewith along a traversedtextile machine. Such a field of illumination is indicated generally inFIGS. 1 3 by the phantom line cone 24.

It is to be recognized that other photosensitive means are known whichhave the capability of functioning as required in the present invention,that detector means may sense phenomena other than reflectedillumination, and that the present invention contemplates the use ofsuch other detector means. By way of example and without limitation,known photosensitive means of possible use in the electrical circuitmeans herein described include such electrical current modifying devicesas photoresistors or phototransistors as well as photosensitive meanswhich give rise to electrical voltages on application of light theretosuch as photo cells. Such photosensitive means are known to respond to awide range of wavelengths of radiant energy, including wave lengthswhich are outside the range visible to human eyesight. in any instance,the present invention contemplates that the photosensitive meansgenerate a pulse electrical signal in response to movement of the fieldof view thereof across a location on a traversed textile apparatus atwhich an end of yarn is present. Typically, the relatively rapidmovement of a relatively bright object such as an end of yarn into andthrough the field of view of a photosensitive means gives rise to arelatively steep rising and falling variation in the electricalcharacteristic of a photosensitive means. Such a relatively steep risingand falling variation, very roughly approximating a square wave front,is referred to herein as a pulse electrical signal generated by thephotosensitive means.

By way of example of phenomena other than reflected illumination whichmay be detected by suitable means and thereby provide pulse electricalsignals indicative of the presence of an end of yarn, it is known thatyarn being formed may create an electrostatic charge and that certaincomponents at each spindle location become heated by formation of endsof yarn. The presence of an electrostatic charge may be detected byapparatus such as disclosed in copending Ser. No. 41,136 filed May 25,1970, entitled Electrostatic Charge Sensitive Ends Down DetectingApparatus and Method" and owned in common with the present application.Detection of components which are heated by formation of yarn at aspindle location may be accomplished as disclosed in US. Pat. No.3,523,414 issued Aug. 11, 1970 and entitled Temperature Responsive EndsDown Detecting and Reporting Apparatus and Method.

in accordance with the present invention, a pulse signal generated bythe photosensitive means or other detector means is received by a signalconditioning means comprising a pulse shaping circuit means electricallyconnected to the photosensitive means. The function of the signalconditioning means is, in part, to shape the characteristics of receivedpulse signals to a predetermined, shaped characteristic. As brieflymentioned above, the pulse electrical signal generated by aphotosensitive means, while recognizable as such, does not have suchsmoothly shaped characteristics as are desirable for compatibility withlogic circuit means of the type discussed more fully. hereinafter. Whenused in conjunction with the configuration illustrated in FIG. 3, thesignal conditioning means further incorporates elements for insuringresponse of the electrical circuit means to movement of the field ofview of the photosensitive means across a location at which a balloon orvibrating length of yarn is present.

Pulses shaped by the pulse shaping circuit means are delivered to alogic circuit means which is responsive to normal traversal of thedetector means for distinguishing between the absence and presence ofends of yarn on a traversed textile apparatus and for generating anoutput pulse electrical signal upon an end of yarn being absent from alocation at which the same normally is present. As pointed out morefully hereinafter, logic circuit means as contemplated by the presentinvention may take several forms in detaiLbut it is a generalcharacteristic of the logic circuit means that a cadenced determinationis made thereby in coordination with traversal of the photosensitivemeans field of view along the length of traversed textile apparatus.That is, the cadenced determination may be time based where the speed ofmovement of the field of view 20 of the photosensitive means along atraversed textile machine is known or may be positioned based where suchmovement is otherwise accurately. indicated.

Upon determination by the logic circuit means that an end of yarn isabsent from a location at which the same normally is present, generationof an output pulse electrical signal by the logic circuit means is usedto control energization of an appropriate output device for reportingsuch condition. Referring specifically to the system and structuredisclosed in aforementioned U.S. Pat. No. 3,523,4l3, one appropriateform of output device may include a solenoid, in which a pin is extendedin response to accumulation of a predetermined count in a counter and totrip a switch on movement over the switch location. Yet anotheralternative output device is radiant energy emitting means to beenergized under predetermined circumstances and for transmittinginformation to a stationary receiver station as described for example inapplication Ser. No. 866,266 filed Oct. 14, 1969, now US. Pat. No.3,595,005 and entitled Information Transmitting Means for Textile StrandEnds Down Detecting Apparatus."

Referring more particularly to the alternative embodiments available forthe electrical circuit means of the present invention, attention isdirected to FIG. 4. A number of alternative arrangements for theelectrical circuit means of the present invention are there set forth inblock diagram form, with various elements to be selected beingidentified by legends in the blocks and with contemplated systems ofinterconnection being indicated by connection of the various blockrepresentations. The photosensitive means 30 as described above isillustrated by the uppermost block. Signal conditioning circuit meansare generally indicated in the block diagram circuit at 31 and comprisean amplifier 32, a tank circuit 33, an integrator circuit 34, and adififerentiator circuit 35. Logic circuit means are generally indicatedat 36 and comprise a resettable oscillator 37 and a gate device 38operatively connected with either a second photosensitive means 39 or anoscillator 40. The final element of the block circuit diagram is anoutput device 41.

Considering FIGS. 1, 2 and 5 together, the electrical circuit means ofthe present invention is shown in a first embodiment and applied to thecombination with a traveling pneumatic cleaner mounted on a track formovement above and along textile strand processing apparatus ofelectrical circuit means in which a cadence signal generating meansproduces a pulse electrical signal coordinated to the position of thephotosensitive means field of view and which signal is fed to adistinguishing means comprising a gate device. The gate device will passan output signal upon a pair of pulse signals being simultaneously fedthereto but blocks passage of any signal upon only one of the pair ofsignals being separately fed thereto. In this particular application ofthe electrical circuit means of the present invention, cadencing ispositively done and is coordinated to the physical position of thetraveling pneumatic cleaner relative to the spindles of a traversedtextile machine. Another embodiment with similar position basedcadencing will be disclosed hereinafter.

Referring to the block circuit diagram of FIG. 4, the circuit now to bedescribed would result from connection of the photosensitive means 30and amplifier 32 to the gate device 38, with the gate device receivingcadence signals from the second photosensitive means 39. Circuitelements in FIG. 5 serving the functions of the block diagrammedelements in FIG. 4 carry the reference characters applied in FIG. 4.

In FIG. 5, the photosensitive means 30 is schematically indicated as aphotomultiplier device. Through a coupling capacitor C1 and a set pointpotentiometer P1, pulse electrical signals generated by thephotosensitive means 30 are fed to an amplifier 32. Amplified signalspassing from the amplifier 32 are directed through suitable couplingmeans to a pair of coupled transistors TAl and TAZ. The transistors TAland TA2 are arranged to function as a circuit for shifting the level ofsignals and squaring the signal to a uniform characteristic forapplication to one of two semiconductor elements arranged as a flip-flopor bistable multivibrator generally indicated at 42. A pulse signaloriginating with the first photosensitive means 30 and passing throughthe circuit elements just described is directed to the bistablemultivibrator 42 through a coupling diode D1, to insure proper polarityof the applied signal. Inclusion of the coupling capacitor C1 betweenthe photosensitive means 30 and the amplifier 32 insures that responseof the pulse shaping circuit means, through which the pulse signalgenerated by the photosensitive means 30 is passed to the bistablemultivibrator 42 is indicative of a rapid change in the level ofillumination applied to the photomultiplier device, such as occurs uponmovement of the field of view thereof across a reflective object such asan end of yarn, rather than being characteristic of a more gradualvariation in the electron flow through the photomultiplier device suchas may be indicative of a gradual change in the general illumination ofthe field of view thereof.

As will be noted from FIG. 2, the track 11 on which the travelingcleaner i0 is mounted for movement above and along the traversed textilemachine 12 has secured thereto spaced apart indicia means in the form ofreflective elements 45. Preferably, the reflective elements 45 arestrips of a retroreflective tape. Each strip of retro-reflective tape ispositioned on the track 11 (or any other desired location) inpredetermined positional relation to a corresponding one of the spindles14 of the spinning frame 12. An auxiliary photosensitive means housing46 (FIGS. 1 and 2) is mounted from a portion of the undercarriage of thetraveling cleaner 10 and encloses the second photosensitive means 39which functions as a second detector and as a portion of the logiccircuit means 36.

The second photosensitive means 39 is illustrated as a photoresistor PR1(FIG. 5) enclosed within the housing 46, together with a suitableelectrical lamp source 48 and a reflective element such as ahalfsilvered mirror 49. By the physical arrangement of the light source48, the reflective element 49 and the photoresistor PRl functioning asthe second photosensitive means 39, light emitted from the lamp 48 isdirected onto the track 11 during traversal thereof by the travelingpneumatic cleaner 10. Upon passage of the auxiliary housing 46 by alocation at which a retro-reflective strip 45 is present, light emittedfrom the lamp 48 is reflected to the photoresistor PR1 to vary theresistance thereof. Upon such variation in the resistance value of thesecond photosensitive means, a pulse electrical signal is generatedwhich is directed to a plurality of interconnected transistors TA3, TA4,TAS, TA6 for conditioning to a desired pulse signal characteristic.Thus, by means of the second photosensitive means 39 and associatedcircuitry, a pulse electrical signal is produced at each location wherean end of yarn should normally be present, and at which the firstphotosensitive means generates a signal indicative of the presence of anend of yarn.

From the circuitry of FIG. 5, it is to be noted that a cadence pulseelectrical signal resulting from reflection of light to thephotoresistor PR1 from a retro-reflective strip 45 is applied throughtwo lines of circuitry. First, through the transistors TA5 and TA6, asignal is applied through an inverter 50 to one side of the bistablemultivibrator 42. At the same time, a signal is coupled to an outputshaping transistor TA7, to be applied through an inverter 51 to the gatedevice 38 which also has applied thereto a signal indicative of theconductive state of onehalf of the bistable multivibrator 42. By meansof a delay circuit including semiconductor elements identified by thereference characters 52 and 53, a pulse passed through TA7 is alsoapplied to the same side of the bistable multivibrator 42 as the pulsesignals passing from the first photosensitive means 30 through theamplifier 32 and the signal shaping transistors TA] and TA2.

The gate device 38 included in the circuitry of FIG. 5 is of the typereferred to as a NAND" gate. Such a gate device has a characteristic ofpassing an output pulse signal only when a pair of signals are appliedthereto and blocking or inhibiting such a signal in the absence ofsimultaneous application of the pair of signals. That is, should thegate device 38 simultaneously receive signals from the inverter 51 andthe bistable multivibrator 82, an output pulse signal is passed throughthe gate device. Should a signal be absent from either the inverter 51or the bistable multivibrator 42, then the other signal applied to thegate device 38 is blocked from passage through the gate 38 to a suitableoutput device.

In operation, movement of the second photosensitive means 39 included inthe logic circuit means past a location at which a retro-reflectivestrip 45 is positioned results in two rapid transitions in theresistance value of the photosensitive means 39, the first occurring atthe leading edge of the finite width of the retro-reflective strip 45and the second occurring at the trailing edge thereof. A pulse resultingfrom the leading edge transition passes through the signal conditioningtransistors 'IA3, TA4, TAS, and TA6 and the inverter 50 to be applied tothe bistable multivibrator 42. This pulse sets the bistablemultivibrator 42 in condition to apply a signal to the gate device 38.Thereafter, as the field of view of the first photosensitive means 30passes a location at which an end of yarn normally is present, thepresence of such an end of yarn gives rise to a pulse signal passingthrough the amplifier 32 and signal conditioning transistors TAl and TA2to be applied to the other ele-' ment of the bistable multivibrator 42,changing the state of the bistable multivibrator and removing the signalotherwise present at the gate device 38. Then, the trailing edge signaloriginating from the second photosensitive means 39 and passing throughthe signal conditioning transistors TA3, TA4,

'TA7 to the inverter 51 is directed to the gate device 38 but will notresult in an output pulse from the gate device because a pair of signalsare not being simultaneously fed thereto.

Should an end of yarn not be present at the spindle location traversedby the first photosensitive means 30, the bistable multivibrator 42continues in such state that a signal is directed to the gate device 38therefrom. Thus, on application of a signal through the inverter 51(resulting from the trailing edge of the reflective strip 45) twosignals are simultaneously present at the gate device resulting in anoutput pulse being delivered from the gate device 38 to a suitableoutput device.

As disclosed in aforementioned US. Pat. No. 3,423,413 with particularreference to FIG. 11 thereof, a suitable output device or reportingmeans may be a counter connected to a signaling solenoid through abinary-digital convertor switch and a latch means of appropriate type.Alternatively, where it is considered desirable to respond to detectionof a single end down, the output device connected to the gate 38 may belatching relay or other element responsive to a signal pulse byenergizing a further circuit. From these briefly stated alternatives, itis apparent that the present invention contemplates any suitable form ofoutput device which may be adapted to the circuitry of FIG. by a skilledelectrical or electronic technician, such as a radio transmitter,computer, etc., whereby the determination of ends down may be reportedas each location is traversed or accumulated and reported at intervals.

Referring now to the embodiment illustrated in FIG. 3, it is to be notedthat the signal conditioning circuit means used in conjunction therewithmust respond to passage of the field of view 20 of the photosensitivemeans along a location at which ends of yarn are present in balloons.Further, the embodiment illustrated in FIG. 3 does not incorporate aphotosensitive means for generating a position coordinated cadence pulseas is done in the embodiment of FIGS. 1 and 2. Instead, electricalcircuit means in accordance with the present invention and operative inthe embodiment illustrated, in FIG. 3 takes the form schematicallyrepresented in FIG. 6.

Referring additionally to the block diagram of FIG. 4, electric circuitmeans useful in connection with the embodiment of FIG. 3 include anarrangement incorporating the photosensitive means 30, the amplifier 32,a frequency responsive circuit which is a selected one of the tankcircuit 33 or the integrator circuit 34, and a logic circuit which is aselected one of the resettable oscillator 37 or the gate device 38 beingsupplied with a cadence pulse from the oscillator 40.

If desired a differentiator circuit may be inserted between the tankcircuit and the resettable oscillator or gate device, respectively, orbetween the integrator circuit and the resettable oscillator or gatedevice respectively. The schematic diagram of FIG. 6 discloses anarrangement in which an integrator circuit corresponding to the circuit34 of FIG. 4 is used in conjunction with an optional diflerentiatorcircuit corresponding to the circuit 35 of FIG. 4 and a resettableoscillator corresponding to the circuit 37 of FIG. 4.

Referring in particular to the elements schematically shown in FIG. 6,photosensitive means 30 takes the form of a photomultiplier devicecoupled through a capacitor Cl and a set point potentiometer P4 to anamplifier 32 in similarity to -a corresponding portion of the circuitdiscussed above with reference to FIG. 5. Pulse signals passing throughthe amplifier 32 are passed to signal conditioning transistors TR] andTR2. In distinction from the arrangement discussed above with referenceto FIG. 5, the movement of the field of view 20 of the photosensitivemeans 30 is along a portion of a textile machine at which the yarn ispresent in balloons, as shown in FIG. 3, and results in generation of apulse train having a frequency characteristic of the rotational speed ofthe yarn balloon. That is, as the end of yarn rotates with the travelermoving about the ring of a ring-spinning frame, relative brightness inthe field of view of the photosensitive means 30 is modulated at a speedreflecting the rotational speed of the end of yarn in the balloon. Thus,during the time that the field of view traverses a particular spindlelocation, a train of pulses of predetermined frequency are generated bythe photosensitive .means 30 and pass through the amplifier 32 and thetransistors 'I'Rl and TR2. In order to distinguish the presence of sucha train of signals, the pulse shaping circuit means included in thecircuitry of FIG. 6 comprises a frequency responsive circuit (integratorcircuit) electrically connected to the amplifier 32 for receiving shapedpulse signals therefrom and for passing substantially unimpeded a pulsesignal indicative of variations in illumination in the field of view 20of the photosensitive means 30 occurring at a predetermined frequencycoordinated to the rotational speed of the ballooned ends of yarn.

As suggested by the block diagram of FIG. 4, such a frequency responsivecircuit may comprise a tuned tank circuit of inductance and capacitanceelements selected to attenuate pulse signals having repetitivefrequencies other than the predetermined frequency or may comprise anintegrator circuit of resistance and capacitance elements selected toattenuate pulse signals having repetitive t'requencies below thepredetermined frequency. In the form illustrated in FIG. 6, anintegrator circuit 34 is provided, formed by a capacitor C2 and aresistor R1. Such an integrator circuit builds a staircase charge on thecapacitor C2 during application thereto of pulse signals at apredetermined frequency, giving a voltage rise coordinated to theparticular predetermined frequency chosen. The integrator circuit isused in conjunction with a breakdown device 55 such as a Diac, whichnormally is nonconductive while voltages applied thereto remain below aparticular predetermined level. Upon the voltage applied to thebreakdown device exceeding the predetermined level, as will occur when apulse train at a predetermined frequency is applied to the integratorcircuit 34, the breakdown device 55 becomes conductive and passes apulse signal onward to further circuit elements.

The distinction between the choice of a tank circuit 33 and anintegrator circuit 34 lies, in part, in the effect of those circuits onpulse trains applied thereto. As contemplated by the present invention,a tank circuit 33 causes an effective shortto-ground for trains ofpulses having repetitive frequencies other than that indicative of thepresence of a yarn balloon or vibrating yarn in the field of view 20 ofthe photoelectric means 30 and if a tank circuit 33 is substituted forthe integrator circuit 34 (FIG. 6) the breakdown device 55 is omitted.

A pulse signal passing from the frequency responsive circuit included inthe signal conditioning circuit means of FIG. 6 passes to an amplifier56 and is then delivered to a single shot monostable multivibratorgenerally indicated at 58, through a coupling capacitor C3 and couplingdiode D2. On application of a pulse signal to the single shot monostablemultivibrator 58, a single output pulse of standardized characteristicsis delivered therefrom to the differentiator circuit 35, composed of acapacitor C4 and a resistor R2. Taken together, the functions of themultivibrator 58 and diflerentiator circuit 35 are to complete shapingof a signal passed through the frequency responsive circuit means to astandardized pulse characteristic. A signal having the desiredstandardized pulse characteristic is then applied to coupled transistorsTRS and TR6 and results in application of a pulse signal of desiredcharacteristics to a resettable oscillator generally indicated by thereference character 37, which functions in the circuit of FIG. 6 as thelogic circuit means.

The resettable oscillator 37 comprises a unijunction transistor 60 andis free running in that the unijunction transistor normally generates anoutput pulse electrical signal at a predetermined time interval,established by appropriate selection of resistance and capacitancevalues included in the oscillator 37 and coordinated to the linearvelocity of the photosensitive means 30 field of view 20 relative to atraversed textile machine. As pointed out more fully hereinafter, thepredetermined time interval is slightly greater than the interval atwhich the photosensitive means field of view normally traverses thespindle location at which ends of yarn are normally present. Timing ofthe predetermined interval is initiated by a change in the conductivestate of a coupling transistor TR7 included in the resettable oscillator37, with such a change in conductive state discharging a timingcapacitorC incorporated in the oscillator 37, in a manner generally known toelectronic technicians skilled in the design and application ofunijunction timing circuits. It is to be noted that the conductive stateof the coupling transistor TR7 is dependent upon delivery thereto of ashaped pulse signal through the transistors TRS and TR6, so thatcadenced resetting of the oscillator 37 by shaped pulse signalsindicative of an end of yarn being present at a traversed spindlelocation inhibits generation of an output pulse signal by the oscillatorIn operation of the circuit of FIG. 6, movement of the field of view ofthe photosensitive means along a portion of a traversed textile machineat which ends of yarn normally are ballooned between stationary androtating guides, as shown in FIG. 3, results in periodic application tothe frequency responsive circuit means of trains of pulses at afrequency coordinated to the rotational speed of the yarn balloons. Uponapplication of a train of pulses having the desired frequencycharacteristic, a pulse signal is passed through the additional signalconditioning circuit means provided and is delivered to the resettingtransistor TR7. Cadenced resetting of the oscillator 37 inhibitscompletion of timing of the predetermined interval which would lead toan output pulse being generated by the resettable oscillator. Upon anend of yarn being absent from a location at which an end normally ispresent, the oscillator 37 is not inhibited, timing of the predeterminedinterval is completed, and a change in conductive state of theunijunction transistor 60 results in generation of an output pulse fromthe resettable oscillator. Such an output pulse is applied to anappropriate output device such as discussed above, to carry out thedetennination of the absence of an end of yarn from the traversedtextile strand processing machine.

The description of the circuits schematically illustrated in FIGS. 5 and6 has encompassed certain major variations in choice available among theblock diagram arrangements suggested in FIG. 4. While it is believedapparent that a skilled electronic technician working from the blockdiagram of FIG. 4 and the illustrative schematic diagrams of FIGS. 5 and6 may carry forward other variations on the electrical circuit means ofthe present invention, it is considered appropriate to point out certainother possibilities including a third embodiment which represents aparticularly direct application of the present invention.

Referring to FIG. 7, it is to be noted therein that an arrangement isproposed in which photosensitive means 30 may be mounted for traversalof the field of view 20 thereof along a portion of a traversed textilemachine in which ends of yarn normally move along fixed paths, somewhatin similarity to the arrangement of FIG. 2. However, reliance is notplaced upon a second photosensitive means and gate device for positionbased cadencing, but a resettable oscillator of the type discussed abovewith reference to FIGS. 6 and 3 is used and cadence is determined byintervals of time corresponding to the yarn end spacing. In the circuitarrangement of FIG. 7, a pulse signal generated by the firstphotosensitive means 30 viewing a yarn moving in a line in its normalposition'is fed to the amplifier 32 through a coupling capacitor C1. Theamplifier 32 and associated passive circuitry conditions the pulse andpasses the same to the resettable oscillator 37 which functions in themanner described with respect to FIG. 6 for the second embodiment. Thusin the absence of a yarn from a location where it normally should be, anoutput pulse is generated.

While the disclosure hereinabove of an embodiment which operates inconjunction with indicia means provided by reflective elements 45 haspointed out circuitry which employs separate photosensitive meansfunctioning as first and second detectors, it is contemplated that asingle photosensitive means such as the photosensitive means 30 mayoperate in conjunction with circuitry which accomplishes cadencing bydistinguishing between two signals passing from the singlephotosensitive means 30. Such circuitry is disclosed, as a fourthembodiment of thepresent invention, in FIG. 8 and wherein thephotosensitive means 30 is electrically connected both to a circuitwhich recognizes a rotating balloon of yarn and to level shiftrecognization circuit means which distinguishes between difiering levelsof response. More particularly, it will be noted fi'om FIG. 3'of thedrawings that the field of view 20 of the photosensitive means 30 passesadjacent not only the rotating balloons of yarn but also passes adjacentthe body of yarn wound about bobbins on the spindles 14. As a result,the electrical characteristics of the photosensitive means 30 change intwo ways at each traversal of the field of view 20 past a spindlelocation at which an end of yarn is present The operation of thecircuitry of FIG. 8 depends upon distinguishing between two suchdifiering responses.

Upon movement of the field of view of the photosensitive means 30 past aspindle location, there is a general shift in the electricalcharacteristics of the photosensitive means 30 occasioned by therelative brightness of the bobbin cap or of the body of yarn wound aboutthe bobbin as compared with the space between adjacent spindles. Such ashift in level of electrical characteristics is distinct from therelatively rapid fluctuation caused by the rotating balloon of yarn.

In FIG. 8, the photosensitive means 30 is coupled through a couplingcapacitor C1 and a setpoint potentiometer PI to an amplifier 32functioning as a portion of signal conditioning circuit means 31.Electrical pulse signals passing through the amplifier 32 are screenedby a tank circuit 33 which passes pulse signals having a frequencyindicative of the presence of a rotating balloon of yarn. This operationis similar to the balloon detecting circuitry described hereinabove withreference to FIG. 6.

The photosensitive means 30 is additionally coupled, through a couplingcapacitor C6 and a second setpoint potentiometer P2, to logic circuitmeans 36 including an amplifier 60. By selection of appropriate settingsand values for the coupling capacitor C6 and the setpoint potentiometerP2, the logic circuit means 36 is rendered responsive to shifts in thephotosensitive means response level. That is, the coupling capacitor C6,setpoint potentiometer P1 and amplifier 60 cooperate for distinguishingbetween a first level of photosensitive means response which isindicative of traversal of a location where ends of yarn normally arenot present (such as between adjacent spindles) and a second level ofresponse indicative of traversal of a location where ends of yarnnormally are present. The greater relative brightness of a bobbin cap orwound body of yarn brings about such a shift in responsive levels.

The level shifts thus recognized are then employed in a manner similarto the pulse electrical signals derived from the photoresistor PR1 inFIG. 5, to reach a gate device 38 through a bistable multivibrator 42and inverter 51.

In a fifth embodiment of circuitry in accordance with this invention,the photosensitive means 30 is coupled, through a capacitor C1 and asetpoint potentiometer P1, to an amplifier 32. Through means of theamplifier and a pair of pulse-shaping transistors TRl and TR2, pulsesignals appear on a conductor 61 as the photosensitive means 30 is movedpast a spindie location at which an end of yarn is present. Theappearance of a pulse signal on the conductor 61 resets a distancecounter 62 as will now be described, in accomplishing position basedcadencing.

The distance counter 62 receives and counts pulses originating from atraveling unit pulse generator 64, preferably a rotation signalingdevice. By interconnection of the device to an idler wheel 65 of tlnetraveling pneumatic cleaner 10, through means of an idler wheel shaft66, movement of the idler wheel 65 along the track 11 by which thetraveling cleaner is supported results in generating of pulses by thesignaling device which indicates the rotational movement of the shaft66. By selection of the pulse train passed from the device to the lineardistance counter 62, pulses received at the linear distance counter 62are correlated in a predetermined manner to the rotation of the idlerwheel 65 and are thereby correlated to movement of the traveling cleaner10 along the track 1 1. The traveling unit pulse generator 64 thusfunctions as a movement signaling means or as a movement controlledoscillator.

With such correlation of pulse transmittal from the traveling unit pulsegenerator 64 to the linear distance counter 62, a predeterminedrelationship is established with regard tothe distance between adjacentspindle locations along the spinning frame 12 at which ends of yarnnormally are formed. Thus, where spindle locations are on a 3 inchgauge, for example, 300 pulses may be delivered to the linear distancecounter 62 from the traveling unit pulse generator 64 during movement ofthe photosensitive means 30 from a position where a first spindlelocation is monitored to a position where a second, adjacent, spindlelocation is monitored. During such movement, the linear distance counter62 counts the 300 pulses received from the movement signal generator 64and, upon a pulse being passed through the conductor 61, is reset tozero and begins a next count.

In the event that the linear distance counter 62 is not reset to zero bythe appearance of pulse on the conductor 61, as when the photosensitivemeans 30 moves past the spindle location at which an end is down, thedistance counter 62 continues to count pulses originating from thetraveling unit pulse generator 64. Thereafter, when the count reaches apredetermined number greater than that correlated to the gauge distanceof the spindle locations, such as 3l0, a pulse signal is passed from thedistance counter 62 through a first exit gate 68. A pulse passingthrough the first exit gate 68 appears on a conductor 70, to accomplishtwo purposes. The first is passage of an output pulse through an endsdown signal or gate 38 to appear on a conductor 61, resetting thedistance counter 62. The pulse appearing on the conductor 70, throughthe first exit gate 68, additionally sets a flipflop formed by a pair ofinterconnected gates 71, 72, to present a continuing signal at an andgate 74.

In the event that an end is down at two adjacent spindle locations, thedistance counter 62 would again fail to be reset by the appearance of apulse on a conductor 61 from the photosensitive means 30. Thereafter, asthe count in the distance counter 62 reached the number of pulsescorrelated to the gauge distance of the spinning frame 12 (or 300 in thepresent example), a second exit gate 75 passes a pulse from a distancecounter 62 to the and gate 74. Upon appearance at the and gate 74 of acontinuing signal from the flipflop formed by the gates 71 and 72 and apulse signal passed through the second exit gate 75, a pulse is passedthrough the or gate 38 to appear on the output conductor. Thus, nocumulative error is introduced in continuing recognition of successivespindle locations at which ends are down.

In the drawings and specification, there have been set forth preferredembodiments of the invention, and although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation.

What is claimed is:

1. In an apparatus which travels detector means along textile strandprocessing apparatus such as spinning frames for locating and reportingends down thereon, an electrical circuit combination particularlyadapted for traversal of a photosensitive means field of view along aportion of a spinning frame wherein ends of yarn normally are balloonedbetween stationary and rotating guides and comprising:

photosensitive means having a predetermined field of view and generatinga pulse electrical signal in response to variations in illumination insaid field of view indicative of the presence of an end of yarn, saidphotosensitive means being mounted for traversal of said field of viewalong a plurality of locations where ends of yarn normally are present,

signal conditioning means comprising pulse shaping circuit meanselectrically connected to said photosensitive means for receiving pulsesignals therefrom and for shaping the characteristics of received pulsesignals, said pulse shaping circuit means comprising an amplifier forshaping to a substantially uniform shaped pulse characteristic pulsesignals which originate from said photosensitive means and have varyingpulse characteristics, and said signal conditioning means furthercomprising a frequency responsive circuit electrically connected to saidamplifier for receiving shaped pulse signals therefrom and for passingsubstantially unimpeded a pulse signal indicative of variations inillumination in said field of view of said photosensitive meansoccurring at a predetermined frequency coordinated to the rotationalspeed of the ballooned ends of yarn, and

logic circuit means electrically connected to said pulse shaping circuitmeans for receiving shaped pulse signals therefrom and responsive tonormal traversal of said photosensitive means field of view fordistinguishing between absence and presence of ends of yarn at traversedlocations and for generating an output pulse electrical signal upon anend of yarn being absent from a location at which the same shouldnormally be present.

2. An electrical circuit combination according to claim 1 wherein saidfrequency responsive circuit comprises a tuned tank circuit ofinductance and capacitance elements selected to attenuate pulse signalshaving repetitive frequencies other than said predetermined frequency.

3. An electrical circuit combination according to claim 1 wherein saidfrequency responsive circuit comprises an integrator circuit ofresistance and capacitance elements selected to attenuate pulse signalshaving repetitive frequencies below said predetermined frequency.

4. An electrical circuit combination according to claim 1 wherein saidsignal conditioning means further comprises a difierentiator circuit of.resistance and capacitance elements electrically connected to saidfrequency responsive circuit for receiving a pulse signal passedtherethrough and for smoothirng such a received pulse signal to astandardized shaped characteristic.

5. In an apparatus which travels detector means along textile strandprocessing apparatus such as spinning frames for locating and reportingends down thereon, electrical circuit means for determining the absenceof ends of yarn comprismg:

photosensitive means having a predetermined field of view and generatinga pulse electrical signal in response to variations in illumination insaid field of view indicative of the presence of an end of yarn, saidphotosensitive means being mounted for traversal of said field of viewalong a plurality of locations where ends of yarn normally are present,

signal conditioning means comprising pulse shaping circuit meanselectrically connected to said photosensitive means for receiving pulsesignals therefrom and for shaping the characteristics of received pulsesignals, and

logic circuit means electrically connected to said pulse shaping circuitmeans for receiving shaped pulse signals therefrom and responsive tonormal traversal of said photosensitive means field of view fordistinguishing between absence and presence of ends of yarn at traversedlocations for generating an output pulse electrical signal upon an endof yarn being absent from a location at which the same should nonnallybe present, said logic circuit means comprising a resettable,freerunning oscillator normally generating output pulse electricalsignals at a predetermined time interval coordinated to normal traversalof said photosensitive means field of view and responsive to receipt ofa shaped pulse signal from said pulse shaping circuit means forinitiating timing of said predetermined interval, said predeterminedtime interval being slightly greater than the interval at which saidphotosensitive means field of view normally traverses locations at whichends of yarn are normally present, so that cadenced resetting of saidoscillator by shaped pulse signals indicative of ends of yarn beingpresent at traversed locations inhibits generation of an output pulsesignal by said oscillator.

6 In an apparatus which travels detector means along textile strandprocessing apparatus such as spinning frames for locating and reportingends down thereon, electrical circuit means for determining the absenceof ends of yarn comprising:

photosensitive means having a predetermined field of view and generatinga pulse electrical signal in response to variations in illumination insaid field of view indicative of the presence of an end of yarn, saidphotosensitive means being mounted for traversal of said field of viewalong a plurality of locations where ends of yarn normally are present,

signal conditioning means comprising pulse shaping circuit meanselectrically connected to said photosensitive means for receiving pulsesignals therefrom and for shaping the characteristics of received pulsesignals, and

logic circuit means electrically connected to said pulse shaping circuitmeans for receiving shaped pulse signals therefrom and responsive tonormal traversal of said photosensitive means field of view fordistinguishing between absence and presence of ends of yarn at traversedlocations and for generating an output pulse electrical signal upon anend of yarn being absent from a location at which the same shouldnormally be present, said logic circuit means comprising cadence signalgenerating means for producing cadence pulse signals correlated to theintervals at which said photosensitive means field of view normallytraverses locations at which ends of yarn are normally present andfurther wherein said logic circuit means further comprises means forreceiving both shaped pulse signals from said pulse shaping circuitmeans and cadence pulse signals from said cadence signal generatingmeans and for distinguishing between receipt of both signals indicatingthe presence of an end of yarn at a traversed location and receipt ofone signal indicating the absence of an end of yarn from a traversedlocation.

7. An electrical circuit combination according to claim 6 wherein saidcadence signal generating means comprises reflective indicia meansspaced in predetermined relation to said traversed locations at whichends of yarn are normally present, and second photosensitive meansmounted for movement with said first photosensitive means and along saidreflective indicia means for generating said cadence pulse electricalsignals in response to reflection therefrom, said indicia and secondphotosensitive means being so positioned relative to said locations ofends of yarn and said first photosensitive means that said cadence pulsesignals are produced in coordination with generation of pulse electricalsignals by said first photosensitive means in response to viewing ofpresent ends of yarn.

8. An electrical circuit combination according to claim 6 wherein saidcadence signal generating means comprises an oscillator generating pulsesignals at a predetermined frequency.

9. An electrical circuit combination according to claim 6 wherein saidcadence signal generating means comprises level shift recognitioncircuit means electrically connected to said photosensitive means forreceiving pulse signals therefrom and for distinguishing between a firstlevel of photosensitive means response which is indicative of traversalof a location where ends of yarn normally are not present and a secondlevel of photosensitive means response which is indicative of traversalof a location where ends of yarn normally are present, whereby saidphotosensitive means cooperates in the origination of both shaped pulsesignals and cadence pulse signals.

10. An electrical circuit combination according to claim 6 wherein saidcadence signal generating means comprises movement signaling means forgenerating a train of pulses correlated to the movement of saidphotosensitive means along said plurality of locations and furtherwherein said signal distinguishing means includes counter means forcounting said train of pulses and thereby detennining the position ofsaid photosensitive means relative to said locations.

1 1. In an apparatus which travels a pneumatic cleaner along textilestrand processing apparatus such as spinning frames for removing lintand the like therefrom, electrical circuit means for locating ends downby determining the absence of ends of yarn normally present thereoncomprising:

photosensitive means having a predetermined field of view and beingmounted for movement with a traveling pneumatic cleaner for traversal ofsaid field of view along a portion of said textile apparatus where endsof yarn normally are present, said photosensitive means generating apulse electrical signal in response to movement of said field of viewacross a location at which an end of yarn is present,

sigrnal conditioning means electrically connected to said photosensitivemeans for receiving pulse signals therefrom and comprising an amplifierfor shaping to a substantially uniform shaped pulse characteristic pulsesignals originating from said photosensitive means and having varyingshaped pulse characteristics, and

logic circuit means electrically connected to said signal conditioningmeans for receiving shaped pulse signals therefrom and for determiningfrom received pulse signals the presence and absence of ends of yarn,said logic circuit means comprising a resettable, freerunning oscillatornormally generating output pulse electrical signals at a predeterminedtime interval coordinated to normal traversal of said photosensitivemeans field of view and responsive to receipt of a shaped pulse signalfrom said signal conditioning means for irnitiating timing of saidpredetermined interval, said predetermined interval being slightlygreater than the interval at which said photosensitive means field ofview normally traverses locations at which ends of yarn are normallypresent, so that cadenced resetting of said oscillator by shaped pulsesignals indicative of ends of yarn being present at traversed locationsinhibits generation of an output pulse by said oscillator.

12. In an apparatus which travels a pneumatic cleaner along textilestrand processing apparatus such as spinning frames for removing lintand the like therefrom, electrical circuit means for locating ends downby determining the absence of ends of yarn normally present thereoncomprising:

photosensitive means having a predetermined field of view and beingmounted for movement with a traveling pneumatic cleaner for traversal ofsaid field of view along a portion of said textile apparatus where endsof yarn normally are present, said photosensitive means generating apulse electrical signal in response to movement of said field of viewacross a location at which an end of yarn is present,

sigrnal conditioning means electrically connected to said photosensitivemeans for receiving pulse signals therefrom and comprising an amplifierfor shaping to a substantially uniform shaped pulse characteristic pulsesignals originating from said photosensitive means and having varyingshaped pulse characteristics, and

logic circuit means electrically connected to said signal conditioningmeans for receiving shaped pulse signals therefrom and for determiningfrom received pulse signals the presence and absence of ends of yarn,said logic circuit means comprising cadence signal generating means forproducing cadence pulse signals correlated to the intervals at whichsaid photosensitive means field of view normally traverses locations atwhich ends of yarn are normally present and further wherein said logiccircuit means further comprises means for receiving both shaped pulsesignals from said signal conditioningmeans and cadence pulse signalsfrom said cadence signal generating means and for distinguishing betweenreceipt of both signals indicating the presence of an end of yarn at atraversed location and receipt of one signal indicating the absence ofan end of yarn from a traversed location. 13. In an apparatus whichtravels a pneumatic cleaner along textile strand processing apparatussuch as spinning frames for removing lint and the like therefrom,electrical circuit means for locating ends down by determining theabsence of ends of yarn normally present thereon comprising:

photosensitive means having a predetermined field of view and beingmounted for movement with a traveling pneumatic cleaner for traversal ofsaid field of view along a portion of said textile apparatus where endsof yarn normally are present, said photosensitive means generating apulse electrical signal in response to movement of said field of viewacross a location at which an end of yarn is present, v

signal conditioning means electrically connected to said photosensitivemeans for receiving pulse signals therefrom and comprising an amplifierfor shaping to a substantially uniform shaped pulse characteristic pulsesignals originating from said photosensitive means and having varyingshaped pulse characteristics, and

logic circuit means electrically connected to said signal conditioningmeans for receiving shaped pulse signals therefrom and for determiningfrom received pulse signals the presence and absence of ends of yarn,said logic circuit means comprising movement signaling means forgenerating a train of pulses correlated to the movement of saidtraveling pneumatic cleaner along a traversed textile apparatus andcounter means electrically connected to said signal conditioning meansand to said movement signal means for counting said train of pulses andfor distinguishing between receipt of a shaped pulse signal prior to acount indicative of the movement of said traveling pneumatic cleaneradjacent a n'aversed location and absence of a shaped pulse signal atsuch count.

14. In an apparatus which travels a pneumatic cleaner along textilestrand processing apparatus such as spinning frames for removing lintand the like therefrom, electrical circuit means for locating ends downby determining the absence of ends of yarn normally present thereoncomprising:

detector means mounted for movement with a traveling pneumatic cleanerand for traversal along a portion of said textile apparatus where endsof yarn normally are present, said detector means generating anelectrical signal in response to movement across a location on atraversed textile apparatus at which an end of yarn is present, and

logic circuit means mounted for movement with said traveling pneumaticcleaner and op'eratively electrically connected to said detector meansfor receiving signals therefrom and comprising cadence signal generatingmeans for producing an electrical sigrnal correlated to the interval atwhich said detector means normally traverses locations at which ends ofyarn are normally present and means for receiving both signals passingfrom said detector means and signals gnassingnfrorn said cadence signalgenerating means and or dis gurshrng between receipt of both sigrnalsindicating the presence of an end of yarn and the receipt of one signalindicating the absence of an end of yarn from a traversed location.

15. Apparatus according to claim 14 wherein said cadence sigrnalgenerating means comprises indicia means spaced in predeterminedrelation to said traversed location at which ends of yarn are normallypresent and second detector means mounted for movement with said firstdetector means and along said indicia means for generating said cadenceelectrical signals in response to traversal of a location at which anindicia means is present, said indicia means and second detector meansbeing so positioned relative to said locations of ends of yarn and saidfirst detector means that said cadence electrical sigrnals are producedin coordination with generation of electrical signals by said firstdetector means in response to traversal of present ends of yarn.

16. Apparatus according to claim 14 wherein said first and seconddetector means comprise radiant energy level responsive devices forremotely detecting the respective presence of an end of yarn and of anindicia means.

17. Apparatus according to claim 14 wherein said cadence signalgenerating means comprises level shift recognition circuit meanselectrically connected to said detector means for receiving signalstherefrom and for distinguishing between a first level of detector meansresponse which is indicative of traversal of a location where ends ofyarn normally are not present and a second level of detector meansresponse which is indicative of traversal of a location where ends ofyarn normally are present, whereby said detector means cooperates in theorigination of said both signals.

18. In an apparatus which travels along textile strand processingapparatus such as spinning frames, electrical circuit means for locatingends down by determining the absence of ends of yarn normally presentthereon comprising:

detector means mounted for traversal along a portion of said textileapparatus where ends of yarn normally are present and for generating anelectrical signal in response to movement across a location on atraversed textile apparatus at which an end of yarn is present, and

logic circuit means operatively electrically connected to said detectormeans for receiving signals therefrom and comprising cadence signalgenerating means for producing an electrical sigrnal at the interval atwhich said detector means normally traverses locations at which ends ofyarn are normally present and means for receiving both a signaloriginating from said detector means and a signal originating from saidcadence signal generating means and for distinguishing between receiptof botln signals indicating the presence of an end of yarn and thereceipt of one signal indicating the absence of an end of yarn from atraversed location.

i t i i UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3, 659,409 Dated May 2, 1972 lnventofls) David W. Saunders It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

C01. 16, line 28, "Claim 14" Should be Claim 15 Signed and sealed this5th day of September 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents USCOMM-DC GUSTO-P59 0.! GOVIINHINY PRINTING OFFICI: IIII0JCl-.\Jl

FORM F'O-105O (0-69)

1. In an apparatus which travels detector means along textile strandprocessing apparatus such as spinning frames for locating and reportingends down thereon, an electrical circuit combination particularlyadapted for traversal of a photosensitive means field of view along aportion of a spinning frame wherein ends of yarn normally are balloonedbetween stationary and rotating guides and comprising: photosensitivemeans having a predetermined field of view and generating a pulseelectrical signal in response to variations in illumination in saidfield of view indicative of the presence of an end of yarn, saidphotosensitive means being mounted for traversal of said field of viewalong a plurality of locations where ends of yarn normally are present,signal conditioning means comprising pulse shaping circuit meanselectrically connected to said photosensitive means for receiving pulsesignals therefrom and for shaping the characteristics of received pulsesignals, said pulse shaping circuit means comprising an amplifier forshaping to a substantially uniform shaped pulse characteristic pulsesignals which originate from said photosensitive means and have varyingpulse characteristics, and said signal conditioning means furthercomprising a frequency responsive circuit electrically connected to saidamplifier for receiving shaped pulse signals therefrom and for passingsubstantially unimpeded a pulse signal indicative of variations inillumination in said field of view of said photosensitive meansoccurring at a predetermined frequency coordinated to the rotationalspeed of the ballooned ends of yarn, and logic circuit meanselectrically connected to said pulse shaping circuit means for receivingshaped pulse signals therefrom and responsive to normal traversal ofsaid photosensitive means field of view for distinguishing betweenabsence and presence of ends of yarn at traversed locations and forgenerating an output pulse electrical signal upon an end of yarn beingabsent from a location at which the same should normally be present. 2.An electrical circuit combination according to claim 1 wherein saidfrequency responsive circuit comprises a tuned tank circuit ofinductance and capacitance elements selected to attenuate pulse signalshaving repetitive frequencies other than said predetermined frequency.3. An electrical circuit combination according to claim 1 wherein saidfrequency responsive circuit comprises an integrator circuit ofresistance and capacitance elements selected to attenuate pulse signalshaving repetitive frequencies below said predetermined frequency.
 4. Anelectrical circuit combination according to claim 1 wherein said signalconditioning means further comprises a differentiator circuit ofresistance and capacitance elements electrically connected to saidfrequency responsive circuit for receiving a pulse signal passedtherethrough and for smoothing such a received pulse signal to astandardized shaped characteristic.
 5. In an apparatus which travelsdetector means along textile strand processing apparatus such asspinning frames for locating and reporting ends down thereon, electricalcircuit means for determining the absence of ends of yarn comprising:photosensitive means having a predetermined field of view and generatinga pulse electrical signal in response to variations in illumination insaid field of view indicative of the presence of an end of yarn, saidphotosensitive means being mounted for traversal of said field of viewalong a plurality of locations where ends of yarn normally are present,signal conditioning means comprising pulse shaping circuit meanselectrically connected to said photosensitive means for receiving pulsesignals therefrom and for shaping the characteristics of received pulsesignals, and logic circuit means electrically connected to said pulseshaping circuit means for receiving shaped pulse signals therefrom andresponsive to normal traversal of said photosensitive means field ofview for distinguishing between absence and presence of ends of yarn attraversed locations for generating an output pulse electrical signalupon an end of yarn being absent from a location at which the sameshould normally be present, said logic circuit means comprising aresettable, freerunning oscillator normally generating output pulseelectrical signals at a predetermined time interval coordinated tonormal traversal of said photosensitive means field of view andresponsive to receipt of a shaped pulse signal from said pulse shapingcircuit means for initiating timing of said predetermined interval, saidpredetermined time interval being slightly greater than the interval atwhich said photosensitive means field of view normally traverseslocations at which ends of yarn are normally present, so that cadencedresetting of said oscillator by shaped pulse signals indicative of endsof yarn being present at traversed locations inhibits generation of anoutput pulse signal by said oscillator. 6 In an apparatus which travelsdetector means along textile strand processing apparatus such asspinning frames for locating and reporting ends down thereon, electricalcircuit means for determining the absence of ends of yarn comprising:photosensitive means having a predetermined field of view and generatinga pulse electrical signal in response to variations in illumination insaid field of view indicative of the presence of an end of yarn, saidphotosensitive means being mounted for traversal of said field of viewalong a plurality of locations where ends of yarn normally are present,signal conditioning means comprising pulse shaping circuit meanselectrically connected to said photosensitive means for receiving pulsesignals therefrom and for shaping the characteristics of received pulsesignals, and logic circuit means electrically connected to said pulseshaping circuit means for receiving shaped pulse signals therefrom andresponsive to normal traversal of said photosensitive means field ofview for distinguishing between absence and presence of ends of yarn attraversed locations and for generating an output pulse electrical signalupon an end of yarn being absent from a location at which the sameshould normally be present, said logic circuit means comprising cadencesignal generating means for producing cadence pulse signals correlatedto the intervals at which said photosensitive means field of viewnormally traverses locations at which ends of yarn are normally presentand further wherein said logic circuit means further comprises means forreceiving both shaped pulse signals from said pulse shaping circuitmeans and cadence pulse signals from said cadence signal generatingmeans and for distinguishing between receipt of both signals indicatingthe presence of an end of yarn at a traversed location and receipt ofone signal indicating the absence of an end of yarn from a traversedlocation.
 7. An electrical circuit combination according to claim 6wherein said cadence signal generating means comprises reflectiveindicia means spaced in predeteRmined relation to said traversedlocations at which ends of yarn are normally present, and secondphotosensitive means mounted for movement with said first photosensitivemeans and along said reflective indicia means for generating saidcadence pulse electrical signals in response to reflection therefrom,said indicia and second photosensitive means being so positionedrelative to said locations of ends of yarn and said first photosensitivemeans that said cadence pulse signals are produced in coordination withgeneration of pulse electrical signals by said first photosensitivemeans in response to viewing of present ends of yarn.
 8. An electricalcircuit combination according to claim 6 wherein said cadence signalgenerating means comprises an oscillator generating pulse signals at apredetermined frequency.
 9. An electrical circuit combination accordingto claim 6 wherein said cadence signal generating means comprises levelshift recognition circuit means electrically connected to saidphotosensitive means for receiving pulse signals therefrom and fordistinguishing between a first level of photosensitive means responsewhich is indicative of traversal of a location where ends of yarnnormally are not present and a second level of photosensitive meansresponse which is indicative of traversal of a location where ends ofyarn normally are present, whereby said photosensitive means cooperatesin the origination of both shaped pulse signals and cadence pulsesignals.
 10. An electrical circuit combination according to claim 6wherein said cadence signal generating means comprises movementsignaling means for generating a train of pulses correlated to themovement of said photosensitive means along said plurality of locationsand further wherein said signal distinguishing means includes countermeans for counting said train of pulses and thereby determining theposition of said photosensitive means relative to said locations.
 11. Inan apparatus which travels a pneumatic cleaner along textile strandprocessing apparatus such as spinning frames for removing lint and thelike therefrom, electrical circuit means for locating ends down bydetermining the absence of ends of yarn normally present thereoncomprising: photosensitive means having a predetermined field of viewand being mounted for movement with a traveling pneumatic cleaner fortraversal of said field of view along a portion of said textileapparatus where ends of yarn normally are present, said photosensitivemeans generating a pulse electrical signal in response to movement ofsaid field of view across a location at which an end of yarn is present,signal conditioning means electrically connected to said photosensitivemeans for receiving pulse signals therefrom and comprising an amplifierfor shaping to a substantially uniform shaped pulse characteristic pulsesignals originating from said photosensitive means and having varyingshaped pulse characteristics, and logic circuit means electricallyconnected to said signal conditioning means for receiving shaped pulsesignals therefrom and for determining from received pulse signals thepresence and absence of ends of yarn, said logic circuit meanscomprising a resettable, freerunning oscillator normally generatingoutput pulse electrical signals at a predetermined time intervalcoordinated to normal traversal of said photosensitive means field ofview and responsive to receipt of a shaped pulse signal from said signalconditioning means for initiating timing of said predetermined interval,said predetermined interval being slightly greater than the interval atwhich said photosensitive means field of view normally traverseslocations at which ends of yarn are normally present, so that cadencedresetting of said oscillator by shaped pulse signals indicative of endsof yarn being present at traversed locations inhibits generation of anoutput pulse by said oscillator.
 12. In an apparatus which travels apneumatic cleaner along textile strand processing apparatus such asspinning frames for removing lint and the like therefrom, electricalcircuit means for locating ends down by determining the absence of endsof yarn normally present thereon comprising: photosensitive means havinga predetermined field of view and being mounted for movement with atraveling pneumatic cleaner for traversal of said field of view along aportion of said textile apparatus where ends of yarn normally arepresent, said photosensitive means generating a pulse electrical signalin response to movement of said field of view across a location at whichan end of yarn is present, signal conditioning means electricallyconnected to said photosensitive means for receiving pulse signalstherefrom and comprising an amplifier for shaping to a substantiallyuniform shaped pulse characteristic pulse signals originating from saidphotosensitive means and having varying shaped pulse characteristics,and logic circuit means electrically connected to said signalconditioning means for receiving shaped pulse signals therefrom and fordetermining from received pulse signals the presence and absence of endsof yarn, said logic circuit means comprising cadence signal generatingmeans for producing cadence pulse signals correlated to the intervals atwhich said photosensitive means field of view normally traverseslocations at which ends of yarn are normally present and further whereinsaid logic circuit means further comprises means for receiving bothshaped pulse signals from said signal conditioning means and cadencepulse signals from said cadence signal generating means and fordistinguishing between receipt of both signals indicating the presenceof an end of yarn at a traversed location and receipt of one signalindicating the absence of an end of yarn from a traversed location. 13.In an apparatus which travels a pneumatic cleaner along textile strandprocessing apparatus such as spinning frames for removing lint and thelike therefrom, electrical circuit means for locating ends down bydetermining the absence of ends of yarn normally present thereoncomprising: photosensitive means having a predetermined field of viewand being mounted for movement with a traveling pneumatic cleaner fortraversal of said field of view along a portion of said textileapparatus where ends of yarn normally are present, said photosensitivemeans generating a pulse electrical signal in response to movement ofsaid field of view across a location at which an end of yarn is present,signal conditioning means electrically connected to said photosensitivemeans for receiving pulse signals therefrom and comprising an amplifierfor shaping to a substantially uniform shaped pulse characteristic pulsesignals originating from said photosensitive means and having varyingshaped pulse characteristics, and logic circuit means electricallyconnected to said signal conditioning means for receiving shaped pulsesignals therefrom and for determining from received pulse signals thepresence and absence of ends of yarn, said logic circuit meanscomprising movement signaling means for generating a train of pulsescorrelated to the movement of said traveling pneumatic cleaner along atraversed textile apparatus and counter means electrically connected tosaid signal conditioning means and to said movement signal means forcounting said train of pulses and for distinguishing between receipt ofa shaped pulse signal prior to a count indicative of the movement ofsaid traveling pneumatic cleaner adjacent a traversed location andabsence of a shaped pulse signal at such count.
 14. In an apparatuswhich travels a pneumatic cleaner along textile strand processingapparatus such as spinning frames for removing lint and the liketherefrom, electrical circuit means for locating ends down bydetermining the absence of ends of yarn normally present thereoncomprising: detector means mounted for movement with a travelingpneumatic cleaner and for traveRsal along a portion of said textileapparatus where ends of yarn normally are present, said detector meansgenerating an electrical signal in response to movement across alocation on a traversed textile apparatus at which an end of yarn ispresent, and logic circuit means mounted for movement with saidtraveling pneumatic cleaner and operatively electrically connected tosaid detector means for receiving signals therefrom and comprisingcadence signal generating means for producing an electrical signalcorrelated to the interval at which said detector means normallytraverses locations at which ends of yarn are normally present and meansfor receiving both signals passing from said detector means and signalspassing from said cadence signal generating means and for distinguishingbetween receipt of both signals indicating the presence of an end ofyarn and the receipt of one signal indicating the absence of an end ofyarn from a traversed location.
 15. Apparatus according to claim 14wherein said cadence signal generating means comprises indicia meansspaced in predetermined relation to said traversed location at whichends of yarn are normally present and second detector means mounted formovement with said first detector means and along said indicia means forgenerating said cadence electrical signals in response to traversal of alocation at which an indicia means is present, said indicia means andsecond detector means being so positioned relative to said locations ofends of yarn and said first detector means that said cadence electricalsignals are produced in coordination with generation of electricalsignals by said first detector means in response to traversal of presentends of yarn.
 16. Apparatus according to claim 14 wherein said first andsecond detector means comprise radiant energy level responsive devicesfor remotely detecting the respective presence of an end of yarn and ofan indicia means.
 17. Apparatus according to claim 14 wherein saidcadence signal generating means comprises level shift recognitioncircuit means electrically connected to said detector means forreceiving signals therefrom and for distinguishing between a first levelof detector means response which is indicative of traversal of alocation where ends of yarn normally are not present and a second levelof detector means response which is indicative of traversal of alocation where ends of yarn normally are present, whereby said detectormeans cooperates in the origination of said both signals.
 18. In anapparatus which travels along textile strand processing apparatus suchas spinning frames, electrical circuit means for locating ends down bydetermining the absence of ends of yarn normally present thereoncomprising: detector means mounted for traversal along a portion of saidtextile apparatus where ends of yarn normally are present and forgenerating an electrical signal in response to movement across alocation on a traversed textile apparatus at which an end of yarn ispresent, and logic circuit means operatively electrically connected tosaid detector means for receiving signals therefrom and comprisingcadence signal generating means for producing an electrical signal atthe interval at which said detector means normally traverses locationsat which ends of yarn are normally present and means for receiving botha signal originating from said detector means and a signal originatingfrom said cadence signal generating means and for distinguishing betweenreceipt of both signals indicating the presence of an end of yarn andthe receipt of one signal indicating the absence of an end of yarn froma traversed location.